The quest for better 'fast find' options
A number of posts are suggesting better ways to recover FDR/CVR data or find the crash site. The prime motivations seem to be 1 - reduce cost of search, 2 - improve speed of accident analysis, 3 - provide quick information for headlines and threads ;-).
It is worth considering that in many (probably the majority) of cases, physical examination of the wreckage is necessary to get to actionable corrective actions. That is, the data either says 'this is the pattern of failure, flight path, and crew commentary' (the what); or the data just stops (tells very little). The why, unless it is human motivated, normally needs an analysis of actual components of the wreck. Additionally, there normally is a very strong desire to recover as many bodies as possible to provide proper closure and respect. As such, regardless of how fast the initial location is identified, there is inevitably an extensive effort with a number of ships and expensive recovery equipment to recover the wreck and human remains. I am not an expert, but I would guess that in every case (other than MH370) the cost of locating the wreck is dwarfed by the cost of recovering the wreck. As such, regardless of the technology for locating or transmitting the FDR/CVR data, the main cost of recovery will not be avoided, so the economic balance is going to be against anything expensive.
It appears in this case that, as a matter of luck not design, an ELT did get off a transmission that localised the crash site, that surface debris was found pretty quickly (maybe one day later than a large dye marker) and it appears that the ULB has been localised within 12 hours of the correct gear arriving on station. Additionally, the aircraft was transmitting its location at GPS accuracy to ground stations every second until very likely the power was shut down, so no matter what extra technology was added, it is not likely the undersea location was going to be known to a significantly higher level of accuracy.
Speculating on the little information we have, I would bet the FDR is going to show a cascading set of faults that are consistent with an electrical fire/short circuit 'somewhere', and then the power being shut down. The CVR is likely to indicate the pilots thought there was a fire and took corrective action, and if it remained powered, which I suspect not, then that they lost control in a very difficult set of circumstances. ... But crucially NOT A CLUE as to what actually failed and why; and therefore, no indication of the corrective actions necessary. However, after recovering the wreckage, analysing the damage and context, the investigators, in due course, will provide a pretty clear view of what failed, why, and some recommended corrective actions.
Investing say $4,000 M ($100k per commercial aircraft - not a lot for any change) fitting slicker locator technology to save a thankfully rare and normally small incremental cost of finding the general crash site (even in the extreme MH370 case the cost appears to be budgeted for $130 M) and saving the initial two weeks of searching, in a process that normally takes over a year to reach its conclusions, seems a poor choice.